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Flexible supercapacitors may replace today's batteries

At the University of Central Florida researchers are working on a process to develop flexible supercapacitors that can eventually replace batteries in portable devices like a smartphone.

The good thing about supercapacitors is that they can deliver instant power and can be charged in a blink of an eye (almost, let's say in 30") plus they have a very long life time, being able to sustain tens of thousands of charge-discharge cycles. Compare this to batteries where the charging time is measured in hours and the number of charge-discharge is measured in hundreds... and you see why this research is so interesting.

There is a catch (there always are...). To contain the same amount of energy of a battery you need a much much larger capacitor (in volume).

A supercapacitors is ... a capacitor. It stores energy by capturing and keeping electrons between two surfaces. The broader the surfaces the more capacity can be stored. To decrease the overall volume researchers have experimented with thinner and thinner surfaces, looking in particular at graphene, whose layers can be just one atom thick. That would provide a huge ratio surface/volume. The battery of your smartphone would be able to contain 120,000 square meters of graphene layer (hence a capacitor with some 30,000 square metres of surface, since it takes two surfaces and the dielectric between them).

However, the researchers have been stumbling on the hurdle of manufacturing such capacitor by integrating a two dimensional material into a product.

Here comes the result from University of Central Florida. The researchers have managed to use million of nanotubes covering each of them with a two dimensional layer. The capacitor consists of those millions sheathed nanotubes.

The do not have an industrial product, yet. This is more a prototype demonstrating the potential feasibility of creating a capacitor based on nanotubes. It will take several more years to move from the idea demonstration to something you can find in your smartphone but the first step has been taken.